Adhesives prepared from radiation curing a composition comprising a single hydroxy polyester reacted with a prepolymer functionalized with a (meth)acrylate and/or isocyanate is known.
U.S. Pat. No. 4,668,763 to Muller et al., May 26, 1987, pertains to a hydroxy polyester which is fluid at room temperature, with a low viscosity, relatively high molecular weight and very low setting points having alkyl side chains in substantially regular arrangement. Preferably, the polyester chains are unbranched or only slightly branched.
U.S. Pat. No. 4,822,829 to Muller et al., Apr. 18, 1989, pertains to radiation-setting (meth)acrylate-functional polyesters prepared from base polyesters which are fluid at room temperature and have molecular weights of 1,000 or more as well as aliphatic side chains bound to the main chain by ester bridges and, in some cases, ether bridges, and in which a maximum of 90% of the original hydroxy groups of the base polyester are functionalized. The radiation-setting (meth)acrylate-functional polyesters are usable for coatings and especially as adhesives free of solvents.
U.S. Pat. No. 5,281,682 to Comforth et al., Jan. 25, 1994, relates to improved radiation curable compositions which comprise N-vinylformamide and an oligomer selected from the group consisting of epoxy-acrylate resins, polyester acrylate resins, polyurethane acrylate resins and mixtures thereof.
Although the ease of application has been improved as a result of developing such low viscosity polyesters, development efforts continue to strive to address improvements of other properties. Accordingly, industry would find advantage in radiation-curable compositions exhibiting a substantial improvement in flexibility, shear resistance at high temperatures, peel adhesion, and wet-out properties.